MECT (twitch-free electroconvulsive shock) is one of the most effective methods for the treatment of depression and has been widely used in clinical practice in recent decades. It has a wide range of indications, from adolescents to the elderly, but the main treatment population is the i-strong. It can be used either alone or in combination with antidepressants, but the efficacy must be maintained with drugs after the course of treatment. People often refer to MECT as “brainwashing” and “using a brainwashing machine to wash away bad moods”, but it is just an image, in fact, they are not the same. The so-called brainwashing does not mean rinsing the brain clean, but rather that an idea has been instilled in a designed way, and this idea is deeply rooted, regardless of whether the idea is right or wrong. Brainwashing, as it is understood, is the process of emptying the brain of bad feelings while leaving the person as ignorant as a newborn baby. MECT is an independent psychiatric treatment method, by giving the human body a short time limited electrical stimulation, causing the cerebral cortex to discharge extensively, promoting a series of physiological changes in brain cells, so that the substances in the brain that control human emotions and behaviors can reach a state of equilibrium again, so that the “bad mood” can be reduced or disappeared, and the knowledge and ideas that have been acquired can be retained. MECT is a method of treatment that can be used to reduce or eliminate “bad moods” and retain knowledge and ideas, while memory may be temporarily impaired. The mechanism of action of MECT is not well understood, but there are several suggestions: (1) The occurrence of depression is related to the disorder of monoamine neurotransmitters (a chemical related to human mood, behavior and sleep) in the brain. In contrast, MECT inhibits abnormal brain activity through extensive cortical firing, increases norepinephrine synthesis and uptake in the body, increases sensitivity to 5-hydroxytryptaminergic neurons, and has several effects on the dopaminergic transmitter system. (2) MECT has a therapeutic effect by bringing the central neurotransmitter system to a new relative balance through a comprehensive and immediate synergistic effect on multiple receptors. (3) We know that in the brain, the hippocampus is an important component of the limbic system, involved in learning, memory, emotional response and vegetative function, and MECT can promote neurogenesis in the hippocampal area, which can have a therapeutic effect by regulating neuroplasticity through brain-derived nerve growth factor. (4) Gamma-aminobutyric acid is an important inhibitory neurotransmitter, which is involved in a variety of metabolic activities in the brain and has high physiological activity, and MECT can play a therapeutic role by affecting gamma-aminobutyric acid-mediated neural circuits.